The solitaire

Overview

The Solitaire is a straight 150WRMS Stereo Power Amplifier or can be offered like the IKARUS as a higher powered [150WRMS] Stereo Integrated Amplifier.

It best embodies the sculptural design and “lack-of-sound” philosophy of Metaxas & Sins.

After over 35 years of work in the field of High End Audio, from the design and manufacturing of entire playback systems to the recording of over 300 acoustic concerts to gain further musical insights, the last thing that artist-designer Kostas Metaxas wanted to produce was “another box with transistors on a heatsink”.

Kostas was dreaming of the most spectacular architecture, design and sculpture he had experienced and wanted to bring that emotional intensity, daring and seductive beauty to an audio amplifier.

As a recording engineer, Metaxas also wanted to “voice it” for extremely realistic recording playback, to be able to reproduce all the nuance and emotion of a musical performance.

His new SOLITAIRE is the result. Machined from a solid block of either aircraft aluminium, copper or titanium, it’s totally bespoke and the modular electronics make it future-proof. Even the circuit boards can be CNC machined from 1mm solid silver coated clear polystyrene.

From the sensual, organic and striking casework [inspired by the stunning work in Sports cars of the 1950’s/60’s of Ercole Spada, as well as the architecture of Hadid, Gehry and Calatrava] to absolutely every part of the amplifier including the circuit, topology, layout and casework has been developed by Kostas Metaxas. It is the logical evolution of his ground-breaking design concepts pioneered in the early 1980’s.

Then, it true “Bugatti fashion”, each and every amplifier is assembled by the master or his sins — either Andreas or Alessandros Metaxas.The individually 5-axis CNC’d “sculptural” enclosure presents a very heavy, solid, inert, non-resonant structure to RFI shield and ultimately protect the delicate electronic signals, driving the noise floor to ultra-ultra-low levels, revealing a wealth of detail that has never been heard before.

Input stage

The fully complementary, dual differential, cascaded input stage is linearized to ensure least distortion over the large volt-age swings to the amplifier input from the preceding preamplifier. A very gradual (6dB/octave) Bessel filter is incorporated at the input to eliminate the needless reproduction of Radio Frequencies. The second voltage gain stage uses considerable local feedback to ensure that large voltage swings from the input stage are accommodated with the least possible distortion. An overall negative feedback of only 11dB is required to stabilise the complete D.C. operating point and reduce distortion at full power to below 0.01% T.H.D. which is primarily composed of second harmonics. A D.C. servo is built around an integrated circuit to monitor the output voltage and ensure absolute D.C. stability at all times.

Output stage

Our triple Darlington output stage uses the fastest power transistors that were previously available, but no longer available since the factory in Japan was destroyed by a Tsunami. Fortunately, we purchased large stocks of these devices 30 years ago.Our printed circuit design borrows techniques from RF and UHF ground plane technology to maximise the speed of current delivery, especially at high frequencies from the ultra high-speed (fT’s 150 MHz) power transistors.

Power supply input & output stage

The input voltage gain stage of the SOLITAIRE is isolated via the high-current output stage via a two stage’ capacity-multiplier’ circuit which uses the beta of the transistors to multiply the filtering effect of the capacitor used. The simplicity of this circuit allows the elimination of any output bypassing capacitors which would otherwise reduce the apparent speed and degrade the sound quality of this amplifier.

Protection circuits

To eliminate the sonic colourations imposed by sophisticated current limiting protection circuits, the SOLITAIR Uses only the short M205 fuse types to protect the high current stages. Apart from the fuses is a four pole relay in series with the loudspeaker connections. If over 0.6VDC is sensed at the amplifier output, the relay is activated until the condition is rectified.

Specifications

FREQUENCY RESPONSE: DC - 5.0MHz (-3dB)POWER OUTPUT: 150WRMS per channel into 8 Ohms with no more than 0.05% T.H.D.DAMPING FACTOR: Greater than 500 wide bandSLEW RATE: Greater than 1000V/us small and large signalT.H.D.: Less than 0.05% 20Hz-20KHzI.M.D.(S.M.P.T.E.): Less than 0.05%SIGNAL/NOISE: -117DBV unweighted input shortedSENSITIVITY: 0.5VRMS in for 150WRMS out (28dB)INPUT IMPEDANCE: 100kOhms in parallel with 11pF

The making of a solitaire

This video traces the creative and manufacturing process of a solitaire, enjoy.